Process for the preservation of wood



Patented Jan. 17, 1928.

UNITED. STATES,

BASILIUS RECTE VASO MALENKOVIG, 0F NEULENGBACI-I, AUSTRIA.

PROCESS FOR-THE PRESERVATION OF W001 10 Drawing.

The subject of the present invention is the application to the preservation of wood, of the chemical compounds which are formedwhen primary aromatic amines act upon the halogen-dinitroderivatives of benzol or its homologues. Since the substances first formed in this reaction are not described in the literature of the subject, it is necessary to explain their nature by an example.

If molecular quantities of a saturated alcoholic solution of a-naphthylamine (which will be colourless provided the preparation be pure), with an equally saturated yellow alcoholic solution of a chlorodinitrobenzol, for example, 2.4-dinitro-l-chlorobenzol are mixed, the mixture of the. two liquids immediately becomes blood red and crystals- Vermilion to, blood red in colour-forming the sole reaction product, separate out. The reaction'has therefore been oneof simple accretion of the components. No free hydrochloric acid can be detected. The empirical" formula of this compound is C H,NH .G I-I,(NO G1, and it may be rearded either as a derivative of dihydroenzol (1 H as represented by the formula (A) or as a compound of pentavalent nitrogen as represented by the following formula (BE derived from ammonium chloride (A) (B) NHCIOH1 H om iii N 1 N0: CuHKNOa):

According to the second hypothesis, therefore, an ammonium base is formed,-as 1n the case of "aliphatic compounds. Instead of mixing the solutions of the two components, it is even suflicient to fuse a mixture of the two; in fact, simple intimate trituratlon in a mortar is enough. The a-naphthylamine may be replaced by ,B-naphthylamine, aniline, one'of the toluidines, xylidines or by,

No matter which.

Application flIed'Dec'ember 16, 1925. Serial No. 75,870.

product is always \el'IlllllOH to blood red. in colour. Examination under the microscope reveals yellowish red, brown-red, Vermilion or blood-red needles.

These compounds are not identical with the corresponding secondary amines, but can all be transformed into the corresponding secondary amines by the elimination of HCl, HBr or H1 as the case may be. In appearance, the secondary amines are the same as the compounds first formed, except that they areoften somewhat darker. The

melting point of the corresponding secondary amines, however, is considerably higher. For example, the substance obtained from mixtures of a-naphthylamine and chlorodinitrobenzol melts below 100 0., whereas the dinitrophenyl-a-naphthylamine obtained therefrom does not melt'below 190.5 C.

In order to transform the substances first formed into the corresponding secondary amines, solutions of the same must be boiled for a long time in presence of substances which split oif halogen acids. The following equations illustrate the conversion:

, The boiling is therefore conducted in presence of an excess of the primary amine, or else a neutralizing agent, such as magnesia, zinc oxide, sodium acetate, etc. is used.

' v If the agents splitting ofi hydrogen that is' to say the ozidizing agents be allowed to act still longer, carbazoles may be formed.

The substances first formed are not described in chemical textbooks, though descriptions are given of the secondary amines preparable therefrom.

Experiments have shownthat, so far as fungicidal properties are concerned, it is immaterial whether use is made of the initial products obtained by simply mixing, fusing or triturating the components, or the products-that is the secondary aminesobtainted therefrom by subsequent expulsion of 2101C.

On the other hand, the selection of the primary materials is by no means immaterial, the degree of activity, apart from the cost, being'the first consideration. It has been found, for example, that the action of the compounds obtained from o:-

' the benzol (or of the toluol or xylol) may be nitrated; and that nucleus must contain two nitro groups, and not one or three. The second nucleus, namely that of the primary amine, whether a benzol, toluol, xylol, naphthalene, anthracene, or still more complex nucleus, must not contain any nitro-group at all. In German Patent 219,942, I have specified the symmetrical tetranitrodiphenyla- Here the second benzol nucleus also is nitrated, and this substance is therefore far weaker in action than those now specified. Moreover, the said patent relates solely to nuclei and derivatives of benzol and its homologues. Again, dinitrobenzol and its homologues (such as dinitrotoluol) form, with aniline, naphthylamine, etc., red necdles having the empirical formula,

These substances, however, only act with the same power as a mixture of their com ponents, and cannot be transformed into the secondary amines. The case, however, is fundamentally different when, as in the present instance, halogendinitrobenzols are employed. As shown in the following table, the activity then largely exceeds that of the mine NH [(),,H (N 0 2 as being active. components: 7

The addition 0! the following percentages prevents the growth 01' Penicilllum Substance and all other fungi on seecharosegelatlne, the surface therefore remalning sterile.

Dlnitrobenzol 0. 050

Dinltrotoluol 0. 045

Chlorodinitrobenzol 0. 050

Aniline -1..-" 0.600

e-Naphthylarhlne 0. 100

fi-Naphthylemlnn 0. 160

Diphenylamine 0. 500

Dinitrophenol 0.060

Dinltroocresol 0. 040

Compounds obtained from molecular mixtures of chlorodinltrohenzol and anilln 0.020

Compounds obtained from molecular mixtures of chlorodinltrobenzol and a-naphthylamlne about 0. 010

Hence the compounds obtained from chlonaphthylamine and chlorodinitrobenzol is rodinitro ben'zol and a-naphthylamine act with approximately five times as much energy as one of the components (chlorodinitro-benzol), or as dinitrobenzol, and about ten times as strongly as the second component (a-naphthylamine). They far exceed the activity of the substances I described in German Patent 219,942. The action of the substances obtained from asix times greater than that of the dinitrophenol so largely employed for the purpose of preserving wood. All the substances resulting from halogendinitrobenzol derivatives and primary amines are very sparingly soluble in water. If used in the form of aqueous solutions, the best'method is to mix with them the solutions of other im regnating agents, such as zinc chloride, :1 ali fludinitrophenol salts.

orides or mixtures of alkali fluorides with solvent for the originating materials (mixed in molecular proportions), or the products obtained by fusion or trituration, or even the corresponding secondary amine.

usual oils are suitable; coal tar oils, brown- It is preferable to use oil as the coal tar oils, water-gas tar oils, mineral oils,

etc. The wood may also he first impregnated with a solution of these substances inoil, and then with water alone (to ensure better distribution of the oil),-with alkalifluorides, with or without addition of salts of the dinitrophenols, or with zinc chloride.

Of the compounds resulting from a-naphthylamine and chlorodinitrophenol, 0.25 kg. per cubic metre of wood will be suflicient, though, for the 'sake of'precaution, a larger amount may be used. f other substances be added, quantities below 0.25 kg. per cubic nifetre of wood will suflice to produce the full e ect."

All the.

What I claim is f 1. Process for the preservation of wood, consistin in that the wood is treated with the reactlon products of an aromatic halogen nitro compound and an aromatic primary amine.

2. Processfor the preservation of wood, consisting in that the wood is treated with the reactlon products of an aromatic halogen nitroi compound and an aromatic primary amine in admixture with another suhconsisting in that the wood is treated with the reaction products of a halogen dinitro compoundvand a'non-nitrated arOmatic primary amine.

In testimony whereof I aflix my'signature.

memos more VASO 'M'ALENKovI. 

